One of the greatest improvements made in dentistry in this century is the use of endodontics to save natural teeth that become abscessed. In the past, when the root canal of a tooth became abscessed, a fairly frequent occurrence, a dentist could relieve the intense pain produced by the abscessed tooth only by extracting the tooth. In the last couple of decades, procedures have been improved to the point that by the practice of endodontics, most abscessed teeth can now be saved.
Endodontics in general consists of treating an abscessed tooth to relieve the abscess by cleaning out the nerve and pulpal tissue in the tooth root canal so as to remove the material that is the source of infection and thereby remove the infection itself from within the tooth and from within the patient's system.
The typical procedure for treating an abscessed tooth in the modern dental practice is to drill a hole through the coronal area to access the upper end of the root canal. The dentist, or endodontic practitioner, then carefully removes the nerve and pulpal tissue from the root canal and shapes the root canal for receiving an inert filler material. Removal of pulpal material and shaping the root canal is accomplished by the use of dental files that are inserted through the opening in the coronal area and manipulated to scrape away and remove pulpal material and at the same time shape the canal to receive the filler material. After a canal has been cleared of pulpal material it must be filled with an inert material to prevent, or at least substantially reduce the possibility of fluids and material from the body entering into the root canal through the root apical area. The standard filler material that has been in use by dentists and endodontists for many years is gutta percha, a naturally occurring plastic-like material that has characteristics that particularly adapt it for use as a filler material although other types of filler materials have been and in the future undoubtedly will be developed.
Effectively filling a cleaned and prepared root canal is an essential step in a successful endodontic operation. Filler material can be injected directly into a root canal such as by means of a manually employed compacting instrument. Others have suggested the use of mechanical injection devices for injecting filler material directly into the root canal. One of the most successful ways of filling a root canal in modern times has been by the use of an endodontic obturator disclosed in U.S. Pat. Nos. 4,758,156 and 4,894,011 by Dr. William B. Johnson. These patents are incorporated herein by reference. These patents disclose endodontic obturators utilizing a carrier in the form of a shaft of solid material that is metal or plastic that has formed thereon filler material, such as gutta percha. The gutta percha is heated such as over an open Bunsen Burner or by other techniques and while in semi-liquid state, the carrier with the adhered gutta percha is inserted into the prepared root canal. This technique introduces the gutta percha into the canal and, by means of the carrier, into the full depths of the canal to the apical area. Further, the physical insertion of the carrier serves to compact and force the filler material into irregular areas of the root canal.
The technique employed in these two patents is typically in the form of an elongated tapered shaft that is inserted into and remains in the tooth root canal.
Carriers can be either metal, fiberglass or plastic and in recent years the use of plastic carriers has increased in preference by some practitioners.
The present invention is directed towards an improved system for filling an endodontically prepared root canal. Additional background material relating to the endodontic preparation of root canals and filling root canals can be obtained from the following previously issued United States and foreign patents and technical art:
PATENT NO. INVENTOR TITLE 674,419 Kinsman Root Canal Filling For Teeth 1,463,963 Miller Root Canal Point 1,469,992 Card Dental Root Canal Point 1,969,808 Lentulo Rotary Plugging Tool 3,318,000 Paris Dental Root Canal Filling Point 3,534,476 Winters Method and Apparatus for Drilling and Filling Root Canals 3,813,779 Tosti Method and Apparatus for Sealing Root Canals and Anchoring Teeth 3,861,043 Lieb et al. Dental Pin 4,353;698 McSpadden Dental Tool 4,397,634 Biggs Surgical Pins and Method 4,457,710 McSpadden Dental Instrument 4,480,996 Crovatto Endodontic Instrument for Dental Root Canal Filling 4,758,156 Johnson Tool for Use in Applying Filler Material to an Endodontically Prepared Root Canal 5,051,093 Fitzmorris Root Canal Filling Device Including Releasably Reusable Inserter Tool CA 1220369 Weisskircher Self-Adapting Retentive Endodontic Build-Up Post CH 513640 Corneo Instrument for Filling Dental Root Canals DE 126184 Beust Dental Root Filling FR 775073 Garnier Filling Paste for Sealing Obturations of the Tooth Crevice FR 2,163,953 Aubert & Gluck Obturator Root Other Cited References: Vol. 4, No. 6 Journal of Endodontics-June 1978 Vol. XXV, New York Odontological The Dental Cosmos P. 185-195 Society Third Edition, Endodontics- Obturation of the Radicu- P. 271-272 Ingle and Taintor lar Space January 1, British Dental Journal- A Newly Designed Root 1980 Negm, Grant et al. Canal Filling Material January, 1 Oral Surgery- Negm Filing Root Canals with 1983 Silve-Percha Cones: A Clinical Study